Fix: Find mailbox with cc email (#4372)

spec/finders/email_channel_finder_spec.rb

@@ -0,0 +1,29 @@
+require 'rails_helper'
+
+describe ::EmailChannelFinder do
+  include ActionMailbox::TestHelper
+  let!(:channel_email) { create(:channel_email) }
+
+  describe '#perform' do
+    context 'with cc mail' do
+      let(:reply_cc_mail) { create_inbound_email_from_fixture('reply_cc.eml') }
+
+      it 'return channel with cc email' do
+        channel_email.update(email: 'test@example.com')
+        channel = described_class.new(reply_cc_mail.mail).perform
+        expect(channel).to eq(channel_email)
+      end
+    end
+
+    context 'with to mail' do
+      let(:reply_mail) { create_inbound_email_from_fixture('reply.eml') }
+
+      it 'return channel with to email' do
+        channel_email.update(email: 'test@example.com')
+        reply_mail.mail['to'] = 'test@example.com'
+        channel = described_class.new(reply_mail.mail).perform
+        expect(channel).to eq(channel_email)
+      end
+    end
+  end
+end